Step-ladder.



- No. 771,840. PATENTED OCT. 11, 1904.

G. R. SHELDON.

STEP LADDER.

APPLICATION FILED FEB. 6, 1904.

N0 MODEL.

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- v D5 Mamet UNITED STATES Patented October 11, 1904.

PATENT OFFICE.

STEP-LADDER.

SPECIFICATION forming part of Letters Patent No. 771,840, dated October11, 1904.

Application filed February 6, 1904. Serial No. 192,317- (No model.) o

To all whom it may concern.-

Be it known that 1, CHARLES R. SHELDON, a citizen of the United States,and a resident of Port Huron, in the county of St. Clair and State ofMichigan, have invented a new and Improved Step-Ladder, of which thefollowing is a specification.

My invention relates to step-ladders composed of two parts hingedtogether; and the objects of my improvement are to provide a ladder inwhich the two parts may be firmly locked together in any desiredposition; to

provide a ladder in which, while the parts are being moved to anyposition, there is no possibility of parts of the hinge'engaging andpreventing free movement, and to provide a ladder-hinge that may bereadily locked and unlocked. I attain these objects by the constructionillustrated in the accompanying drawings, in which Figure l is a generalview of the ladder. Fig. 3 is a plan of the hinge in its lockedposition. Fig. 4 is a cross-section of the hinge in the unlockedposition. Figs. 2 and 5 to 11, inclusive, are views of details. Fig. 12is a view of another form of the hinge-locking means. Figs. 13 and 14are details of the same.

Similar reference characters refer to like parts throughout the severalviews.

It is often desirable to have a step-ladder the stiles of which can belocked together at various angles. particularly for use on polishedfloors, where there is great danger of the stiles spreading. It is alsooften of great value if the rear stiles are provided with treads orrounds, so that these rear stiles can be folded out parallel to thefront stiles, practically forming an extension ladder, particularly whenthe parts can be locked in this position.

In the construction shown the front stiles 1 are provided with the usualtreads 2 and top 3. To these stiles, near the upper ends, on the in- 4ner sides, are secured the plates 4:,having circular flanges 1 providedwith projecting radial teeth 5. A rod 6 passes through these plates,through the center of the rings of teeth, and through the tube 7, whichextends across be tween the two plates 4.. The rear stiles 8 are 5provided with rounds or treads 9, and at their upper ends, on the innersides, are secured the plates 10,also provided with flanges 10, havingprojecting radial teeth 11. The rod 6 passes through these stiles andplates through the center of the rings of teeth. One end of the rod 6 isscrew-threaded and is engaged by the threaded washer 12, which bears onthe outer side of one of the stiles 8. To the outer side of the otherrear stile is secured the Washer or plate 13, which has an opening forthe rod 6 and has two parallel lugs 14, between which fits loosely thehandle 15, which is pivoted on the end of the rod 6. These lugs preventthe handle and rod from turning relative to the rear stiles and washers12 and 13. This handle is cam-shaped at its pivot end and serves to lockthe teeth of the plates together. In the space formed by the flanges 4and 10 of the plates and surrounding the rod 6 are the springs 16, whichserve to force the teeth apart entirely free from each other when thehandle 15 is turned up. The elasticity of the rear stiles between therod 6 and the upper round 9 is sufficient to permit the springs to forcethe plates apart sufiiciently to entirely disengage the teeth. The lugs14: on the sides of the handle prevent the handle from swinging, andthus unscrewing the rod 6out of the washer 12. The friction between thiswasher 12 and the sides of the stile is suflicient to hold it in place.In case of wear or shrinkage, turning the washer 12 will quickly adjustthe various'parts.

The numberand depth of the teeth on the plates may be varied as desired,and it will be seen that the stiles can be locked in any desiredposition, and by reason of the rigidity and strength of this look thestiles will break before the plates will slip with reference to eachother. The stiles can be locked at any angle to each other, ranging fromnaught to one hundred and eighty degrees.

Another form of my invention is shown in Figs. 12, 13, and 14. Theplates 4 and 10 and the springs 16 are similar to those of the otherform. The washer 13 is replaced by a second washer, 12. The pipe 7 iscut in two and the inner ends secured in a cup 18, having a central bolt19. The rods 20 screw into the washers 12 at their outer ends and havetheir inner ends bent to fit into cam-slots 21 of the cam 22, which isprovided with a handle 23 and which is revoluble in the cup 18, beingheld in place by the bolt 19. Turning the handle inthe direction of thearrow, Fig. 12, will permit the springs to force the plates and teethapart. Turning the handle back will lock the plates together.

Having now explained my invention, what I claim, and desire to secure byLetters Patent, is

1. In a step-ladder, the combination of the front stiles, plates securedto the same having circular flanges provided with radial teeth, the rearstiles, plates secured to the same having flanges provided with radialteeth to engage the teeth upon the plates of the front stiles, a rodpassing through the plates, a tube on the rod to hold the plates on thefront stiles in position, springs on the rod in the spaces between theplates to disengage the teeth, a screw-threaded washer on one end of therod outside of one of the rear stiles, a plate having lugs, on the outerside of the other rear stile, and a handle pivoted on the other end ofsaid rod having an eccentric to force the teeth into locking engagement,said handle fitting between said lugs.

2. In a step-ladder, the combination of the front stiles, a platesecured to each stile provided with radial teeth, the rear stiles, aplate secured to each rear stile provided with radial teeth and adaptedto engage the corresponding plate on the front stile, a tube for holdingthe inner plates from approaching each other, means to force the teethof adjoining plates into locking engagement comprising a rod passingthrough openings in the plates and the tube, disks on said rod on theoutside of the rear stiles, one disk secured to a rear stile and havinglugs to prevent the rod from turning in the rear stiles, and aneccentric on one end of said rod and rotatable between said lugs,substantially as described.

8. In a step-ladder, the combination of the front stiles, a platesecured to each stile having a flange provided with teeth, the rearstiles, a plate secured to each rear stile having a flange provided withteeth, a rod passing through openings in said plates, means on said rodto force the teeth of each plate on the front stiles into engagementwith the teeth of the corresponding plate of the rear stiles, and aspring between each pair of plates to force the plates apart anddisengage the teeth.

4. In a step-ladder, the combination of the front stiles, a platesecured to the same provided with teeth, the rear stiles, a platesecured to the same provided with teeth, means to force said teeth intoengagement with each other, and a spring between the plates to forcesaid teeth out of engagement with each other.

In testimony whereof I havesigned my name to this specification in thepresence of two subscribing Witnesses.

CHAS. R. SHELDON.

In presence of- ALEX MOORE, SAu D. PEPPER.

